Based on an instructional model that has been demonstrated to enhance transfer of learning in other content domains, we designed and implemented a series of “invention” activities for general chemistry. During these activities, students work with data sets that highlight contrasting cases to invent formulas, procedures, and other general rules regarding topics that have not yet been discussed in lecture. Students’ participation in these activities prepares them to learn with deeper understanding when the topics are discussed in lecture, and has also revealed areas of student difficulty that were surprising to instructors. We will present some of the activities that we have developed, as well as results of formative assessments of students’ understanding and the activity revisions that have been prompted by these results.